


Actions Leave Echoes

by twistedthicket1



Category: Undertale (Video Game)
Genre: Agender Frisk, Angst, Birthday Parties, Complete, Fluff, Gen, Nightmares, Oneshot, Post-Pacifist Route, Sans is kinda depressed but it's ok cause he has family, Sans-centric, parenting
Language: English
Status: Completed
Published: 2016-04-21
Updated: 2016-04-21
Packaged: 2018-06-03 16:42:22
Rating: Teen And Up Audiences
Warnings: No Archive Warnings Apply
Chapters: 1
Words: 8,361
Publisher: archiveofourown.org
Story URL: https://archiveofourown.org/works/6618340
Author URL: https://archiveofourown.org/users/twistedthicket1/pseuds/twistedthicket1
Summary: <blockquote class="userstuff">
              <p>Sans doesn't like talking about complicated things. He categorizes his nightmares as "complicated", given the fact that the majority are about things that have never technically happened. How does one talk about the fact that they're flinching away from a kid because in another timeline, they kill everyone you love?</p><p>Worse, how do you console said kid when they have nightmares about you?</p>
            </blockquote>





	Actions Leave Echoes

**Author's Note:**

> Hi there.
> 
> So... yeah. I've fallen into this fandom head-first. I blame my friends. >.>''  
> This story is a long one but it's been battering around in my head long enough, so I decided to publish it.  
> Any glaring mistakes are mine, so please feel free to point them out ^_^ I'm thinking of writing more for Undertale as I've just finished both Pacifist and Genocide and frankly... I'm floored by how many emotions I felt while playing. 
> 
> I hope you all enjoy ^_^

 

 

 _The grief was a fire, and though you were made of bone and hollow, you swore it consumed you. It ate you from the inside out, crawling inside of his chest and expanding from your ribs to your throat to your mouth. You tasted it, and it tasted like flame. It tasted blue and hot with_ **_Magic._ ** _It_ **_burned._ **

_You spat it out, infused it into your words so that your tongue tasted sparks and your eyes burned blue. With it, was the indelible sense that this had all been said before._

_How many times?_

_How many times had you watched-_

_No._

_Don’t think about it._

 

 _“Kids like you, should be burning in_ **_Hell._ ** _”_

 

 _A shadow grinned. Dark eyes shone from the dim safety of the shade of a pillar. Golden sunlight spilled into the room, but the person before you stayed in the darkness. The only light you could make out was the glint of a weapon coated in Dust. Your hands tightened at your sides, and something inside of you cracked and splintered._ **_Dangerous._ **

 

_The Human moved out into the light, and it was at once someone you knew and someone you didn’t. Frisk. Chara. Their faces blurred for you, in this world, and a mixture of terror and hatred, black as oil spilled from you in a scream of fury. With it, your blasters formed. The last thing you saw before white-blue flame washed out everything from your vision to your hearing, was a red soul._

 

Sans woke with a vicious jerk, his hand automatically coming up to cover his mouth and to stem the hoarse shout that wanted to rise up in his throat. His movement caused the harsh scraping noise of his chair to echo loudly. Nervously, his eyes flicked about, taking in the familiar walls around him. His room. He was in… his _new_ room. The one on the Surface.

 

It was strange, how a place that had been his home for almost three months now could still feel dreamlike compared to his nightmares. He rubbed at his face, the glowing numbers of his alarm clock cheerfully telling him the time.

**2:06 AM.**

 

Welp. He’d be lying if he didn’t admit that he’d woken up at more acceptable times in the past. Then again, like most monsters he found himself still adjusting to the concept of “Night” and “Day”. He had grown up in a world where time was told via marked measurements.

Well… when time bothered to move straight.

 

He clicked his tongue against his teeth then, phalanges tapping against his desk. He looked down at what he had been writing, familiar Wingdings print. Incomprehensible to most, but really that was the point. The ink hadn’t dried properly before he’d drifted off, and now some of the writing stained the edge of his jacket with black. The paragraph drifted off, a snippet of a sentence:

_Measured time anomalies appear to be centred around two individuals. Due to memory-loss of shifted time, it is unknown who the subjects are._

 

An old entry then, he vaguely remembered settling down to update it. He paused a moment before collecting his pen, his hesitance drawn from the lingering echo of the nigtmare ( _but it wasn’t a nightmare, was it? It was another_ **_timeline-_ ** _)._ Carefully, he printed out a single line, ignoring the niggling voice in the back of his head that hissed that it was a blatant _lie._ He fought the tremor in his hand, and eventually when he was finished, settled in for a night of forced wakefulness.

 

 **_FRISK CAN BE TRUSTED._ ** The notebook eventually read, printed in block capitals.

**_FRISK WON’T HURT ANYONE._ **

**_THEY WILL NOT RESET._ **

 

_(But they already had… just not in this version of reality)._

 

****

On a normal day, Sans’ morning consisted largely of hanging out with his brother. This was by no means a hardship, as Papyrus and Sans got along like two limbs, working together in tandem. Breakfast was a fixed routine, largely involving Sans doing his utmost of keeping Papyrus from completely destroying their kitchen while cooking (a harder task than one might think).

 

Today, Papyrus was attempting to make pancakes. Sans watched his brother move about the kitchen idly from the island they had built together in their new home. The tall skeleton seemed to be enjoying himself enough, although he was adding a rather strange amount of meat sauce into the pancake mix. Eh, Human food. He wasn't sure if it was the conventional way of going about making pancakes, but Sans would also be the first to admit that he subsisted largely off of greasy take-out from Grillby’s (now Grillbz, a high-end restaurant on the other side of Ebott).

 

“SANS. DID YOU KNOW THAT APPARENTLY THE HUMANS HAVE A “PANCAKE DAY?” IT’S NEXT WEEKEND, ACCORDING TO ALPHYS.” Papyrus asked while perusing through the cookbook Undyne had bought him. Sans grinned up at his brother, a slow and lazy thing.

“I didn’t, Pap. But looks like it just sort of _crêped_ up on us.” His brother made an offended noise.

“THAT WAS AWFUL. YOU’RE AWFUL.”

“Now, now, no need to _flip._ ”

 

If possible, Sans only grinned more widely. Like a Chesire cat, he seemed infinitely pleased with himself. Papyrus groaned aloud, flipping his pancakes over. They sizzle, a sickly-sweet smell of burnt grease and sugar filling the air. Sans stared into his mug of coffee, strangely having grown attached to the Human substance over the past few months. It was a bit like drinking liquified HP, it gave the same crackle of energy that Monsters tasted when regaining energy.

It also made Papyrus less worried over him if he didn’t happen to sleep much the night before. Though, it did little to hide the lines of stress that seemed permanently etched into Sans’ bones.

 

He took another sip, and then glanced at his watch. It was a fairly new thing, and the bright Adventure Time logo was something that screamed Alphys. A “Christmas” present, she had called it. It stated he was running late, but that wouldn’t really be a problem. He stood up from his chair, making his excuses. Papyrus didn’t really mind. His voice was cheerful as he waved his spatula, spattering meat juice onto the hardwood floor.

 

“SAY HELLO TO THE TINY HUMAN FOR ME.”

Sans looked up, and found his gaze lingering upon the bright red cape that was wound about Papyrus’ neck. For a moment, just a moment, he envisioned it clasped in his hands, covered in Dust and left forgotten on the snowy ground. He swayed where he stood, blinking the images’ haze away.

 

Looking at his brother, Sans grit his teeth and forced a somewhat wan smile. He dug his hands into his pockets to hide their trembling.

“Sure thing, buddy.”

 

****

 

The thing was, Sans knew he had Bad Days. Even before Frisk had stumbled into their world, he wasn’t exactly the most cheerful person. His own past was admittedly complicated, and he had already more than his share of involvement with messing with the natural order of things.

 

He didn’t hate Frisk for what they had at one point done. How could he, when he had also apparently done cruel, unspeakable things in rage. He loved the kid, loved them for what they had done for their people, for their friendship and for themselves.

That didn’t mean a part of him, small in the back of his mind didn’t still fear them.

 

Sans didn’t remember everything, but he dreamed of pasts that no longer existed, sometimes. He had once had a job that had trained him to be aware of when things weren’t quite right. It seemed that even if while awake he couldn’t remember, his subconscious still liked to keep track of how many timelines it had taken to get where they were. Like a video recorder, his mind had taken to making up for the sense of wrongness by having him relive the events in dreams.

A subconscious track record.

_You feel your sins crawling on your back-_

“Sans.”

 

Blinking, the skeleton realised that he had crossed through a few shortcuts without really noticing. A familiar face and head of dark hair caught his eye. Frisk stood at the edge of Toriel’s lawn, school bag in hand. They were looking at him expectantly, and it was then that Sans remembered his duty. Right. School.

He had been volunteered to walk Frisk to school during the weekdays, as Toriel had to leave much earlier than most to open the building, and many of the other Monsters were attending classes themselves or working.

 

“Hey, kiddo.” Sans murmured, approaching. Frisk smiled in their quiet way, waving in greeting. They were wearing a brightly-coloured sweater today, all pinks and blues and yellows. In the middle was a white star. It looked warm to Sans, if a bit oversized. Likely, it was handmade by a certain goat-mom. “You ready to head out to school and learn things?”

Frisk made an amused face, nodding brightly.

 

“Mom’s teaching us about chemistry. She’s been explaining cleaning supplies and why ammonia smells so strong and cleans things.”

“Well, that sounds pretty basic.” Frisk snorted, giggling. Their grin split across their face.

“Mom would love that one.”

“Well, _ion_ full of science puns.” Sans admitted, shrugging slightly. Frisk covered their mouth, trying to stop the giggles. They glanced up mischievously at their skeletal friend.

“Careful, if Undyne hears you making those jokes again she’s going to have a _bone_ to pick with you.”

Not bad. Sans chuckled, feeling some of the weight of the nightmare lesson. He reached out to cuff the top of Frisk’s head, instead running one hand absently through their hair. The kid beamed at him, obviously pleased.

 

Frisk. gestured in the direction of the sidewalk. As they held out their hand, Sans felt a small shiver run up his spine. He firmly crushed the fear, and after only a moment’s hesitation wrapped the warmer fingers up in his own. The kid talked as they walked, skipping along beside him. Frisk liked skipping, and dancing in general. They also enjoyed telling Sans about all the drama twelve year olds seemed to get into at school.

 

“Tauran wants me to go to their sleepover, but I’m not sure if I wanna go.” Sans vaguely recognised the name as a kid of one of the dog Monsters. He wasn’t sure which, though.

“Feeling shy?”

Frisk wrinkled their nose, shaking their head before explaining.

“No, it’s just. They’re far away so I’d have to actually stay over.” Their voice softened “I don’t like leaving Mom for that long.”

Sans regarded Frisk carefully through a side glance. There was something else, but he had learned that Frisk was a bit of a private kid. Pushing tended not to have the desired result, and instead they would often become more recalcitrant with information.

“I’m sure Tori wouldn’t mind you hanging out with your friends for a few days. Heck, you go to Undyne’s and Alphys’ all the time.”

 

Frisk shook their head, seeming frustrated at being unable to properly articulate their feelings.

“That’s different.” They muttered, and a part of Sans understood. Wordlessly, he hummed. It was a vague tone, neither agreement nor dissuasion with Frisk’s actions. Knowing he wasn’t one for decisiveness either, Frisk lapsed into silence. 

 

Something must have given the kid strong feelings however, because he could sense the SAVE they made as he walked them to school. The energy from it alone sent shivers wracking along his spine.

 

****

_You’ve always been one to bend rules. In your morality, in your fighting style._

_Personally, if you’re going to be bothered enough to fight, it doesn’t make sense to you to follow regulations. Who_ ** _did_** _that? Well, aside from your brother. Yet that was what made Papyrus so amazing to you. He never actually_ ** _wanted_** _to hurt anyone._

_You wished you could say the same for yourself._

 

 _If you were fighting, you were going for_ **_blood._ **

 

 _Even if it meant unravelling time. Past, present, future, none of it mattered in this battle. All of it mattered. Like a shuttering flashlight, you and Frisk_ **_(Chara, it’s CHARA not FRISK, DAMMIT-)_ ** _moved through shortcuts, tearing into each other’s attacks. Fast, too fast- you couldn’t see them-_

_A hiss of breath behind you. You ran your shield of bones up unthinkingly. In the same moment, the Human lost their sense of balance with the next shift of time._

 

_In this round, you killed them. In this round, the Human's bones shattered under your attacks, mounted like an animal on a spear._

_It didn’t matter, though, because in a moment all Chara had to do was RESET._

 

_The next round, you didn’t bother to fight it at all._

 

Sans started, looking up and finding that somewhere along the way he had ended up wandering. Luckily, there were a lot less shortcuts made in Ebott than down below it. It was difficult to get lost, even if Sans’ power was unpredictable and often prone to slight miscalculation (it had not been his intention to fall into the river, even if Papyrus had used it as a chance for an impromptu swimming lesson).

He could see that he was in a park, and that his thoughts must have turned at some point to food. This was where Bluebell had set up shop, if memory served correctly.

 

He found the Nicecream seller at the edge of the park, handing out desserts to a small cluster of children both Monster and Human alike. Sans waited patiently for them to disperse, knowing that most Human children still found his skeletal form just a little bit off-putting. Bluebell perked up upon seeing one of his regular customers, and he was quick to get Sans his usual order.

 

“One Cinnabun Chip with extra sprinkles.” Sans would be the first to admit his usual was generally loaded with as much sugar as possible.

“How’s our Human Ambassador doing?” Bluebell leaned against the counter to his cart, a pleased smile on his face. Sans bit into his icecream, a lack of gums making it relatively easy to do so (it never failed to horrify Alphys, much to his amusement).

“Seems to be doing well.” The skeleton answered noncommittally.

“Their birthday’s coming up, right?”

Sans grinned, nodding in agreement.

“That’s right, the big thirteen. Supposedly important in Human years.”

 

Bluebell nodded sagely, as if most Monsters weren’t still crawling around at that age. To Sans, he estimated that thirteen years of age was probably around one hundred years for his kind. A Mark of heading towards adulthood, but still far behind.

“Your group planning anything for them?”

“Tori wants to do a surprise party. It’s probably going to be at Asgore’s. His place is bigger. After my brother wants the Human to stay over at ours since he wants to show them a new anime series. Pap’s already doing research into something Humans call “The Happy Birthday Song”. It’s like some kind of chant to bring good fortune.” In truth, Papyrus’ version of the tune sounded vaguely menacing, but they had until “Pancake Day” (which fell on Frisk’s birthday) to fix that.

 

The Nicecream vendor hummed in consideration, their blue rabbit ears twitching in interest.

“Sounds like a good time. Tell them I say hi- my business has never been better since coming up here.”

Sans nodded, finishing the end of his cone. He crumpled the wrapper up in his hand and handed Bluebell a gold piece.

 

****

_What was the point?_

_What was the_ **_point_ **

**_WHAT WAS THE POINT WHAT WAS THE POINT WHAT WAS THE POINT WHAT WAS THE POINT WHAT WAS THE POINT WHAT WAS THEPOINTWHATWASTHE P O I N T-_ **

 

_You screamed as Gaster dissolved before your eyes, literally torn apart by his own machine._

_You screamed when Chara struck Papyrus, who until the end didn’t really want to fight._

_You screamed when they stabbed you with their knife, the blade piercing through your jacket, lodging itself into your ribs._

_You screamed as Flowey held you in place, and you watched Frisk die._

_Again._

_And again._

_And Againandagainandagain-_

 

_You screamed as you felt your world RESET, tumbling into white and darkness and waking up with no memory of why you were screaming._

 

_You screamed._

_But nobody came._

 

****

“I-I don’t think this is a good idea.”

Alphys stuttered, wringing reptilian hands together nervously. She looked at Papyrus’ car, in which sat not Papyrus but Undyne, grinning maniacally. Beside her, Sans’ mo-ped hummed, making a peculiar rumble that only meant that it had been tampered with (read: improved).

 

Sans looked up at Alphys, revving the engine experimentally. The moped purred, a sound between a jaguar and metallic machinery.

“ _I_ think it’s an _excellent_ idea.” He said, grin only widening as Undyne cheered from the driver’s seat. The smell of asphalt and gasoline filled his nose, sharp and bitter. His eyes slipped shut for a moment, and Sans felt inexplicably _real._

Behind him, Frisk curled their fingers into the fabric of his jacket. He could sense rather than see their smile of anticipation. They were all but bouncing in their seat.

 

“Aw, c’mon Alphys.” Undyne reasoned at her girlfriend, her good eye looking up at her pleadingly. “You’ve done the math right, you _know_ you have. And any damage to Pap’s car Sans can fix right up.”

Thank god for that mechanics class.

“It’s not the car I’m worried about.” Alphys muttered uneasily, her gaze flicking to Frisk then away. The kid for their part didn’t seem to notice, already leaning forward to point excitedly at the ramp Sans and Undyne had constructed.

 

It was quite a sight. Made of plywood and a likely dangerous amount of nails and Magic, the ramp glowed faintly green. Undyne’s powers held it largely together, along with some of the special glue that Sans had developed in his lab. It stood at its peak nearly six feet high, and if calculations were correct then it aimed for a soft mound of earth a bit beyond.

“Frisk’ll be fine. They’re with me. And your calculations are never wrong.” Sans assured. Undyne agreed, and even Frisk themselves seemed to sit up a little bit straighter. It was as if they were trying to look older, more capable of protecting themselves.

 

“U-Um. W-w-well…” Alphys struggled, adjusting their spectacles “M-m-my calculations h-have been wrong… though not o-oft-”

“You need to have more faith in yourself, babe!” Undyne crowed. “You’re _brilliant,_ and this looks _awesome,_ and I am going to _destroy Sans in this race.”_

It was possible Sans had made it into a bit of a bet. Well… a rather large bet. He had needed a way to get Alphys to help. He simply wasn’t as skilled at the practical aspects of science.

 

Frisk spoke up then, their dark eyes alight with anticipation.

“I won’t tell Toriel _or_ Asgore. _Please?”_

The promise of having no consequences from the collective goat-parentals seemed to be the final nail in the coffin that was Alphys’ confidence. She slumped, sighing through her teeth and clutching her tail. She slowly moved out of the way, having agreed beforehand to be the judge of the winner. Edging towards the borders of the woods, she gave one more feeble warning.

“F-Frisk. Be C-careful.”

 

In response, Sans felt the warm sensation of a SAVE being created.

Who knew that a death trap of a ramp and a modified mo-ped could fill someone up with Determination?

 

“On your mark.”

Undyne growled, shifting the gears of the car. Pap would be mad that she wrenched it like that, but Sans could fix it.

“Get set.” Sans replied. The mo-ped let out a shrill squeal as he squeezed the gas.

“G-GO!” Alphys completed, motioning with her arm.

 

The two vehicles took off like a shot. Sans felt the whip of the wind against his bare skull, and he grinned. Sometimes, time only sat so well against his bones if he was moving too quickly for it to follow.

Undyne’s tired screeched loudly behind them, only a second or two away. Sans leaned forward, shouting for Frisk to _“Hold on!”._ His bony thumb flicked a switch on the bottom side of the gear shift, and everything began to shudder and shake. Frisk let out a yelp of surprise as the mo-ped suddenly shot forward, and their eyes widened as they realised:

The entire vehicle had just passed through one of Sans’ shortcuts.

 

Sans felt the gulp of air that Frisk inhaled by his ear, sharp and clear. Yet he didn’t think much of it. Instead he kept his eye on the goal, beating Undyne. He could sense another shortcut coming up, and sped into it from the side. In the process the tires of the mo-ped kicked up mud. Particles of it floated in the brief span of nothingness between realities. The skeleton laughed, feeling exhilarated. Behind him, Frisk echoed the sound, breathy and reckless.

 

Except there was one thing about the shortcuts.

They weren’t always reliable.

Sans felt the front wheel of the mo-ped strike the edge of the ramp, and had a second to think - _Oh, FUCK-_ before he was pitched forward. Going head over handlebars, the skeleton flipped out into open air.

 

Yet that wasn’t what made something cold inside of Sans twist. Despite his low HP, his body was still relatively sturdy, compared to that of a Human’s. Yet that was the problem, because he realised in a flash. Frisk was no longer holding on to his jacket.

Suddenly, Sans closed his eyes and saw a thousand different versions of the same result- the kid’s body, broken and lifeless and destroyed beyond repair.

_Just give up. It’s what I did._

 

He lashed out with his Magic without thinking, eye alighting blue as he grabbed onto Frisk’s soul with an iron will. He halted their plummet to the ground, cutting off gravity. The hard wrenching of his power struck him like a blow to the side, but Sans hardly cared. He sucked in a sharp breath through his teeth, already floating safely towards the ground. Frisk was a few feet above him, drifting downwards at a similarly sedate pace. They weren’t facing Sans, and they seemed frozen in shock.

_Or injury._

The skeleton swallowed back a curse.

 

Someone screamed both of their names. Alphys, most likely. Sans couldn’t really hear much past the crackle of his Magic moving through him. He landed slippered feet on the forest floor, but Frisk didn’t land as smoothly. This was because as they approached the ground their soul suddenly _jerked,_ and Sans let go in reflex. Frisk landed on their knees, but they quickly scrambled back an extra few feet. It took the skeleton a second to realise _why._

Frisk was looking up at him through the fan of their lashes, quivering like a violin string plucked. A cold sweat broke on the back of Sans neck at the look they levelled him, filled with fear and panic.

His eye was still glowing, he realised. His Magic was bright enough to tinge the outline of his skeleton pale blue. Frisk was staring at him, seeming prepared in a moment to dodge.

 

_I don’t want to fight you. I won’t fight you!_

 

Sans only had time to suppress his magic, letting it gutter like an errant candle. He made sure to carefully face Frisk while doing so. Then Undyne and Alphys were there, and the tension between them was forcibly severed. Sans felt the familiar exhaustion that swept over him when he’d used his Magic, and he slumped in an effort not to just completely pass out. He was a puppet with his strings cut, and any other time the thought would have amused him. Now, he just felt vaguely ill.

“Aw, Frisk-” He began, but the sound of his voice caused the kid to flinch.

 

“Woah, are you guys ok?!” Undyne had parked the car a few feet from the ramp, and at a glance it seemed to be mostly intact. This was at least compared to the mo-ped which had apparently overheated with all the shortcut Magic and had begun to smoke (it had landed directly in the dirt pile though, so points to Alphys for accuracy). Frisk didn’t answer Undyne’s question, and so Sans found himself responding on autopilot. He blinked, eyes pinpoints as he flicked his gaze over to the fish woman’s direction.

“We’re alright. Got a few joints rattled but otherwise we both seem to be okay. Frisk?”

 

The kid blinked at their name as if they didn’t quite recognise it for a moment. An uneasy smile worked its way to their lips. They brushed the dirt off of their knees, getting to their feet slowly. The entire time, Frisk kept Sans in their line of sight.

 

****

To say that everyone was in trouble was an understatement.

Toriel didn’t take kindly to anyone possibly injuring their adopted child, even if Frisk had in part been all for it. They had been forced to tell her thanks to the state of Frisk’s clothing, the mud in their hair a sure sign that all of them had been up to something. Even Sans jokes hadn’t really deterred Frisk’s goat-mom from chiding them all like school children (not even when Sans admitted that he found the whole situation rather humerus).

 

As a result, Sans didn’t see Frisk for the rest of the week until the eve of their birthday. He considered the fact that it was possibly for the best. He couldn’t seem to shake off the imprint of the kid’s face from his mind, wide-eyed and in an instant not _there._

Sans _knew_ he had nightmares, he’d been having them long before Frisk even came to the Underground. Yet somehow, he had missed the fact that there was someone else who remembered the time jumps. If anything, Frisk’s memory would be even _better._

 

There was a sour feeling developing in the pit of his nonexistent gut, and he wasn’t entirely sure what it was made up of. Like baking soda and vinegar, it bubbled up and tasted bitter at the back of his mouth. He didn’t have much time to reflect on it during the day, however.

Mettaton had made it back to town in time for the kid’s birthday.

 

“IT’S SO EXCITING TO HAVE A CELEBRITY LIVING CLOSE BY, SANS.” Papyrus was beyond thrilled. In fact, he couldn’t seem to shut up about it. His brother’s childlike enthusiasm made Sans smile, despite the unease he had felt as of late. Papyrus was looking to get another autograph, despite the fact that he already had about seven of them (perks of knowing the star personally). Mettaton despite his ego never seemed to mind, they got along well with Papyrus because of their honest enthusiasm, as well as their clear adoration for them.

 _“~My fans are the reason I go on!~”_ The robot would often say in his typical dramatic fashion.

 

Sans considered pointing out the fact that Mettaton really had no choice _but_ to go on, being a ghost after all.

 

****

 _“If I could actually_ **_kill you_ ** **,** _I would.”_

 _“Erasing all that’s left…_ **_That’s why I’M HERE-_ ** _”_

**_“We’re both just killers, aren’t we.”_ **

 

“Sans!” The skeleton jumped, blinking back to the present. The evening air was warm, and he stood beside Papyrus, outside of Asgore’s front door. He looked at the package in his hands, brightly wrapped ribbon and dark blue wrapping paper. Right, birthday. Pancake Day.

 

Asgore smiled down at them, his hulking frame in the doorway somewhat awkward but no less friendly. His kind brown eyes took in Sans’ gift and Papyrus’ box. Inside, a pancake-cake had been made (luckily with some guidance from Toriel).

“Welcome, come in, please.” Asgore gestured inside, where a warm glow emerged. Friendly voices were already speaking, chatting away with one another. Sans heard Tori and Undyne, as well at Mettaton’s robotic laughter. Sounded like the party was already well under way.

 

“WHERE’S FRISK?” Papyrus asked upon stepping inside, and sure enough a small body soon shot across the floor, running to envelop the tall skeleton in a hug. Frisk pressed their messy brown hair against the skeleton’s leg, offering them a huge grin. Sans watched as his brother scooped the kid up to their shoulders, offering them a good vantage point to wrap their fingers into his scarf.

“HAPPY BIRTHDAY, HUMAN. MY BROTHER AND I BROUGHT YOU GIFTS, AND HUMAN TEXTBOOKS SAY YOU’LL SOON BE GETTING TALLER.”

Frisk certainly seemed to hope so. Their expression brightened at the prospect, and they wiggled a little in anticipation before their face turned towards Sans.

 

The skeleton was expecting… well he was expecting a variety of reactions upon seeing his face again. Sans would have understood apprehension, he would have even understood fear. What he wasn’t anticipating was for Frisk to give him an equally wide smile, filled with excitement.

“Sans!” They laughed, crawling down from Pap’s shoulder’s to embrace the shorter of the skeleton brothers. Sans tentatively returned the embrace, noting that perhaps the kid had gotten taller after all. Already their chin could rest on their shoulders if they leaned towards him.

“Ugh, you need to stop growing.” He complained good-naturedly “This bag of bones soon won’t be able to lift you.”

 

Frisk giggled, and they pulled away to regard Sans carefully. There seemed to be an unwritten question written into their features. It was as if they were asking if everything was ok. The skeleton made his smile a little more real, and he cuffed a hand through their hair warmly. With his other hand, Sans shrugged over the gift.

“Happy birthday, Frisk.”

 

The Human regarded the blue package with interest, a grin on their features.

Frisk’s smile, their _real_ one, was nothing like Chara’s.

 

****

Asgore seemed delighted by the amount of people crammed into his roomy house. The king had always enjoyed good company, and even Toriel, for all of the strain between their relationship, hadn’t made a fuss over the location. The king poured tea for everyone and offered snacks, doing his utmost to be a good host.

 

Most of the Undergound was here, it felt like. There were the usual suspects, Mettaton and Blook seated on the couch in deep conversation, Alphys talking animatedly with Toriel over something. It looked like a board game of some kind. The TV was on, and seated in front of it were a collection of Monster and Human children, all talking and laughing with one another. There were presents strewn like gems across the glass coffee table, and Asgore's massive furniture made an impressive climbing structure for the more energetic children to get their energy out.

There were more adults outside, seated on the patio and sharing snacks. The sun was out, and everything was being saturated in the mellow glow of evening.

 

Sans found himself being tugged along by the sleeve, Frisk guiding him towards Toriel. The motherly goat-monster was dressed in a lavender dress, a change from her preferred robes. She looked up and smiled upon seeing the shorter skeleton being brought forward, causing Alphys to look over as well. Toriel greeted them warmly.

“Sans, it’s _ice_ to see you.” the goat-monster laughed as she offered the skeleton a cold lemonade, and Sans felt the familiar anticipation at the prospect of having someone to kid with. He accepted the drink happily, glancing to Frisk and winking.

“Nice to see you too, Tori. I was just telling the kid what their gift was.”

“And what would that be?”

“Being another year older.”

Frisk snorted, and held up their gift to shake it. It made an obnoxious jingling sound, and the kid’s eyes lit up in delighted surprise.

“I hope it isn’t something _too_ rambunctious. I would like _some_ sleep within this century, after all.”

 

There was a mighty crash then, and Sans looked over to see that Undyne and Papyrus had banded together in a dangerous combo to face the horde of children. The noise had come Papyrus, who had been commandeered as a climbing tree. A fallen continent, the kids were rapidly overwhelming him into a dog pile for tickling (how bones could be tickled, Sans still didn’t know).

Frisk set down their present upon the table carefully before taking off towards the group, charging Undyne head on with a small battle cry of their own. The fish-woman roared in greeting upon impact. Alphys excused themselves then, obviously intent on taking photographs to save for fond memories (or perhaps blackmail).

 

“How are you fairing, then?”

Toriel’s voice was lowered in the way that adults tended to favor when they were asking something that their children necessarily didn’t wish to hear. The tone of it though friendly, was enough to send suspicion skittering along Sans’ bones. He regarded her carefully, taking a sip of his lemonade before replying.

“No worse than usual. Tibia honest, s’nice to just have a day off from my usual lazing about.” He had slept last night? That, at least, had been a bonus. Keep the jokes, keep it light. Sans preferred that to real conversation, if at all possible. It seemed though that it just wouldn’t be his luck, tonight.

 

Toriel seemed to sigh, and an expression of uncharacteristic frustration passed her features before smoothing over apologetically. She glanced at him, shrugging slightly before explaining.

“You’re as bad as Frisk, you know. Both of you.” Before he could ask as to what she meant, Toriel gestured to the seat beside her. Sans sat, something in the goat-mom’s expression that was frighteningly similar to her “scolding” face. He had a feeling he was not going to enjoy this conversation.

Sure enough, Toriel seemed intent on getting to the point.

“I want you to tell me if Frisk stays up tonight. Please.” Toriel tacked on the pleading note as an afterthought, dark eyes glancing towards Sans then away. She regarded her paws carefully, and it was clear that she was searching for the correct way in which to phrase things. “They’re not one to complain, and they would never admit it… but Frisk is struggling with something.”

“What could the kid be struggling with?”

 

Sans asked carefully, although he spoke to his lemonade as he questioned Toriel. He knew very well what might be keeping the kid up, and mixed feelings buzzed inside of his skull. He wouldn’t wish those kinds of nightmares on anyone, but the fact that it was the kid made a sharp sense of guilt squeeze inside of him. That, and the acute knowledge that if Toriel knew about the times he attacked Chara… attacked her _kid,_ she would not be looking at him with such pleading eyes.

The fact that Toriel was only noticing Frisk’s issues now, implied that Sans’ mo-ped catastrophe had affected them more than they’d let on.

 

“I don’t know.” Toriel answered truthfully, and her tone was sorrowful. “At first I thought… it was something to do with before the Underground. A memory… or a dream of a time before. But now…” She breathed deeply in exasperation. “It feels like more than that. Frisk… they won’t _tell_ me.” Sans heard in Toriel’s voice her genuine distress. He wondered to himself what it must feel like, to feel as though there was something huge you were forgetting. Something you had no hope of ever remembering _(Because it never happened and it never_ **_will_ ** _happen and Toriel’s alive and so’s Papyrus and Chara never_ **_existed in this  t i m e l i n e_ ** _-)._

“You think _I_ can talk to them?” Sans broke the thoughts off, his voice tinged with disbelief.

 

Toriel heard it, and she smiled at the skeleton slightly. It was not an entirely happy expression, and it was the kind of face that made Sans uncomfortably certain that he was about to have to make a promise.

“You and Papyrus were the first people Frisk met outside of the ruins. If they cannot trust me… I hope that they could trust _someone._ ”

If Sans could cock an eyebrow in disbelief, he might.

“Looks like with great puns comes great responsibility, then.”

She smiled at him gratefully, seeing acceptance as reluctant as it might be.

“Thank you, Sans.” Toriel murmured. Sans waved off the appreciation with a small shrug. He downed the rest of his lemonade, the liquid feeling heavy in his nonexistent stomach.

_Don’t thank me just yet._

 

It was at that moment that a scream of joy erupted over from the kitchen. The children, like sharks circling a metaphorical kill, had found Papyrus’ and Toriel’s Pancake-Cake.

 

****

The cake was actually pretty good, and soon presents were opened. The larger crowd of people went home after food, and as a result the smaller group of Monsters that Frisk had come to closely befriend watched them unwrap their gifts. From Undyne, there was a bicycle with a bright red flame on it, and from Alphys a collection of manga. Toriel had gotten Frisk a cooking apron, and Asgore had gotten them a tea set with pretty gold flowers painted on its side. Mettaton’s gift had been a bit more dramatic in nature, combining with Napstablook’s present to reveal new headphones and an early release of the robot’s new CD.

Frisk held up the massive headphones to their ears, marvelling at the sound quality of them. A few of the Monster and Human kids gave gifts too, and as a whole Frisk looked entirely overwhelmed by such riches.

 

They thanked everyone effusively, both with words and hugs, which were returned to the kid without hesitation. Still, Sans’ gift was left for last due to its mysteriousness. Frisk thumbed the blue ribbon that held it together thoughtfully for a moment, before casting the skeleton brothers an inquisitive glance. Sans kept his silence, while Papyrus seemed to vibrate in place from his seat on the sofa cushions. Though his main gift had been the cake, he’d still been really excited to see Frisk’s reaction to his brother’s present.

Frisk tore the paper carefully, seeming to revel in the crinkly sound it made. The box inside jangled with its contents, and soon the kid had revealed what was making all the racket.

 

Sans watched as Frisk unearthed the glow in the dark solar-system models Sans had put together, their eyes wide in childlike awe at the amount of detail. Each planet (pluto included) was hand-painted, brightly coloured and cheerful. Frisk held Neptune between their fingers, looking up at Sans with a mingling of disbelief over his effort, and joy.

“You wanted a birthday party,” the skeleton joked, aiming for levity “So all of us _planet._ ”

 

Sans recognised the expression that crossed the kid’s features, and he had a moment to brace himself before the planets were placed carefully on the ground. Frisk lunged at him, wrapping their arms about his neck tightly and burying their face against his shoulder. The group of monsters about them chuckled at the display of affection, but Sans was frozen to the ground. It took him a full second to return the embrace, and when he did he felt awkward, the motion not often used.

Frisk’s voice was quiet, too quiet for anyone else to hear. Yet it was thick with emotion as they mumbled into Sans’ jacket.

“Thank you.”

 

It took the skeleton a while to realise that Frisk was thanking him more for the freely returned hug, than for his gift.

 

****

_Golden sunlight spilled into the royal hall, casting warmth on a grisly scene. Yellow tile had been stained red._

_You stared apathetically at the figure lying crumpled upon the ground, cold sweat still sticking to your bones from exertion. Immobile and lifeless, Chara looked almost like a kid. Their form was smaller, when they were twisted as they were upon the floor. Bones impaled them, still burning blue Magic. To you, the Human looked like someone you once knew. Or perhaps, the vague outline of them, now eaten through and rotten to the core._

_The image blurred, and suddenly_ **_it was_ ** _someone you knew_ **_._ **

 

_You didn’t know what had changed, but in an instant, you knew somehow that you had done something unfixable. Chara was gone, and in their place was a kid in a blue sweater, olive skin._

_Frisk._

_Dark eyes stared lifeless up at the ceiling, bloodied lips parted in a silenced scream. They held not a knife in their hand, but a wooden stick. It was shattered in several places._

_If you could throw up, you would have._

 

Sans woke to the blue wash of a TV screen in the dark, still going long into the night. It had been abandoned by its viewers somewhere in the late hours of the evening, but still it cheerfully went on autopilot, playing episodes of Mettaton’s show. Out of habit of looking for him, Sans glanced to the floor, where Papyrus had passed out in a heap of blankets and pillows. Papyrus was snoring, another strange quirk that seemed to defy his anatomical limits. Sans smiled a little at the way his brother was sleeping, curled up a bit like a massive burrito.

That’s right, he and his brother and Frisk had all gone back to his home after the party.

 

Sans scanned his basement, picking out an empty pile of blankets. He frowned, and perhaps it was the echo of his dream but the skeleton rose to his feet, searching for Frisk. Aside from the show playing, the basement was silent. The pile of blankets looked as though it hadn’t been slept in, though Sans had thought the kid was asleep before he’d nodded off.

The floorboards creaked with his first step, and he caught the tail end of a small inhalation, coming from behind the armrest of the couch. He listened as there was a small shift, as if the person was making themselves as small as possible. Ok then, perhaps it was time for a more strategy-based method of confrontation. Keeping his voice even, Sans spoke.

“Penny for your thoughts?”

 

There was a pause, then Frisk seemed to sigh to themselves. Their head popped up from the other side of the couch, peering at Sans reluctantly, as if they thought they might be mad. Sans snorted, tilting his head to the side.

“Surely I’m not that scary, am I?”

He realised too late it might have been the wrong thing to say. Frisk hunched, seeming to deliberate for a moment to themselves. Something must have kept them from hiding back on the other side of the couch, perhaps the fact that they had already been caught out. Sans could see them sucking up their determination.

 

Frisk turned towards them, walking over Papyrus’ snoring form on quiet, socked feet. Sans settled himself back down onto the sofa, grabbing a blanket and offering it to Frisk before they curled up beside him. After a second of hesitation they took it, draping it over their form much like a cape. Frisk leaned their cheek against Sans’ shoulder, and the warmth from a Human body seemed to saturate deep into the skeleton’s bones, even through their jacket.

 

The two of them sat in relative silence for a while, both of them staring at the TV without really absorbing what was on. There was something about a quest, a fair bit of glitter involved. Sans suspected Papyrus had gotten this DVD from Alphys. A fight scene went on for a bit, in which the two main characters duked it out using larger than life weapons. Each strike made a rain of colourful sparks hiss around them.

“It’s...It’s not like that. Not in… not for real.”

Frisk’s voice whispered into the dark, eyeing Papyrus nervously. Sans held little fear over the issue, his brother could sleep like the dead. Still he found himself speaking in a hushed tone, copying Frisk’s posture of curling up so his knees brushed his chin.

“No,” He said flatly, staring at the television “It’s not.”

 

More silence, the kind that was thick and oppressive. Sans hated these kinds of conversations. The kind that made you want to grit your teeth and pray that the other person would just drop the topic. His skeletal fingers intertwined together about his calves, and he reminded himself that he had technically been the one to initiate. Damn his tendency of offering Toriel promises.

“Goat-Mom’s on my case, y’know.” He softened his tone “Seems to think you’re about to become a permanent member of ‘Insomniac’s R Us’. If you are, you’ll have to speak to one of the managers.”

Frisk cracked a small smile.

“You’d know, you’re probably the second in command.”

 _“Third,_ actually.” Sans grinned. Frisk looked at him, and it was clear they were trying very hard not to snort unattractively and wake up Papyrus.

 

“I don’t hate you.” They blurted, and just like that the good humour seemed to fade. Sans smile became more strained, and Frisk’s eyes were suspiciously leaky (human distress was both fascinating and gross). Once the tears started, the kid didn’t seem to have much control over them. Frisk’s face twisted into grief, and their hands bundled up in the sleeves of their favourite sweater. “I don’t hate… I love all of the Monsters. I love mom… I love dad…I love you and Undyne and A-Alphys b-but I still… I-”

 

“Chara got into your head.” Sans interrupted, watching out of the corner of his eye as Frisk’s chin quivered. “You explained it to me when we first got out. You weren’t in control. You fixed it in the end, and that’s what matters.”

It was the same explanation that Sans had told himself many times when his own memories twisted and tangled in false timelines. You couldn’t control what had happened, and what mattered was that it was _fixed._ Yet Frisk seemed further uncertain by his demeanour, and their hands fisted in their lap as they bowed their head.

“I almost didn’t.” They whispered hoarsely. In the shadow of the TV, Frisk’s face was pale like a ghost’s. “Chara… their personality got stronger every time I hurt someone. I could _feel_ it. They _enjoyed_ killing things. Their Determination smothered mine. I-I killed you all. H-how could you.. I didn’t even give Papyrus a chance!”

Sans didn’t like to dwell too long on the possibility that Frisk could have refused to RESET to find a happy ending. He couldn’t remember everything, but he had distinct memories of the hollowness he had felt upon facing the empty child. The only thing that had fuelled him forward, was the knowledge that he couldn’t afford to let such a creature leave the Underground. Not if he wanted to face his brother again. To RESET now… even the concept of it was a nightmare. His brother forgetting the many things that he _loved_ about the sun and the sky and his friend’s happiness… It would be too much for him to handle for long.

 

“Kid,” Sans murmured, not looking at Frisk now. He didn’t want to see their expression. “What do you see, when you look at me?”

“What do I…” Frisk trailed off, clearly hesitant about the change in topic direction. They paused for a long moment, quietly considering. “I see the Judgement Hall.” They murmured “And… and your Magic.”

“What else?” Sans gently nudged, keeping his posture loose and comforting. Frisk considered, brows lowering in thought.

“Your hot dog stands...and that Word Jumble.” Frisk grinned a little then, and Sans chuckled with the memory. His eyes were gentle pinpricks of light as he explained.

 

“When I think of you I also think of a lot of heavy things. Thoughts that sometimes, keep me awake or scare me,” The admittance caused Frisk to look at him with guilt and concern, so Sans hurried to finish. “But I also think of good things. Like the fact that you took on that demented flower for all of us, and kept going even when monsters killed you. You RESET Chara, before they could do something permanent.” His voice lowered “You spared my brother, when you got a second chance to. For that ending, I would have traded my soul.”

 

Frisk was crying then, and it was just the leaky, awful sobs that Sans usually found frustrating to deal with. Now though, he couldn’t really bring himself to care. It was without thinking that he found himself gathering up Frisk against his side, the two of them using the blanket to block out some of the noise of the outside world. Frisk cried for the better part of a half hour, and when it finally did subside they were victim to hard shudders. The kid sniffed noisily, a wet-sounding laugh emerging from their lips.

“I’m c-crying worse than Napstablook.” They offered a watery smile.

“I read somewhere that elevators can make ghosts happy.” Sans grinned in reply. Frisk cocked their head to the side, confusion etched upon their features.

“How so?”

“They lift the spirits.”

 

Frisk snorted, the sound even worse due to the amount of snot in their system. They wrinkled their noise in distaste even as Sans laughed out loud. “Ew.”

“Hey kid?” Sans asked. Frisk looked at him with a vaguely resigned air of someone expecting another pun. The skeleton’s voice was abruptly quiet.

“We all love you, too.”

 

A voice interrupted their blanket pow-wow brightly.

“YES, HUMAN. I, THE GREAT PAPYRUS, AND ALL OF MONSTER-KIND ADORE YOU. WAIT, WHY WAS THAT BROUGHT INTO QUESTION? ALSO, WHAT TIME IS IT? WHY ARE YOU AWAKE?”

Both Frisk and Sans turned to look at the skeleton who was sleepily sitting up on the floor. Papyrus, not really understanding the situation but seeing the Humans tearful face turned to look at Sans in reproach.

“BROTHER! WHAT DID YOU SAY TO CAUSE THE HUMAN TO CRY? WAS ONE OF YOUR PUNS TOO AWFUL FOR EVEN FRISK TO BEAR?”

“Ouch, bro.” Sans replied “I’m Bear-y hurt by that implication.”

_“SANS!”_

  
Frisk laughed then, and it was a loud and bright thing in the quiet of the skeleton brother’s home.


End file.
